Intertenancy Wall System

A simple and flexible acoustic and fire-rated wall system based on tried-and-true materials for faster construction.

The Masons Intertenancy Wall System is based on our Enviro AAC (autoclaved aerated concrete) panels – a dense yet lightweight material with proven acoustic and fire-stopping performance. The system is easy to work with, giving builders workflow flexibility and construction efficiencies. It is fully NZBC compliant for both fire resistance (FRR) and sound transmission (STC).


Multi-unit residential, terrace houses, apartments, aged-care facilities, commercial.

The Enviro™ AAC panel

The Masons Intertenancy Wall System is based on Masons Enviro™ AAC panel – a 50 mm thick panel tested to and compliant with AS/NZS1530.1. It is manufactured from cement, sand, lime and water which is aerated with an expanding agent. Soft blocks are moulded from the mixture and then sliced into the required panel size and cured in a steam pressure autoclave for up to 12 hours.


  • Fully FRR & STC compliant
  • This system meets and/or exceeds the New Zealand Building Code’s minimum requirements for both fire rating and sound transmission class. It has been reviewed against the NZBC for fire performance by IGNIS, one of Australasia’s foremost fire engineers, and scored a rating of 90/90/90 on walls up to 10 m high. Acoustic engineers Marshall Day reported a lab performance of 64 dB – higher than the minimum STC requirement of 55 dB for intertenancy walls.


  • Easy to use, flexible and fast
  • The Masons system is construction friendly and designed for simplicity and flexibility. As few as two builders can install the system, and installation can be flowed around other work on-site. No weather protection is needed for the AAC panels when work stops, making on-site storage simple.


  • Designed for buildability
  • The system can be installed up to three stories continuously, without interruption, and there is often no need for extra accessories or fiddly work at mid-floors junctions. Services can be run down the framing on either side of the AAC panels, and materials be carried in smaller parts when site access is difficult. The ACC system is easier for everyone on the job. 

* Penetrations to the Masons Intertenancy Wall System: fire and acoustic must be engineered for fire rating and to preserve acoustic performance and installed by suitably qualified persons. 

Scope and limitations
For scope of use, limitations, conditions and statement of building code compliance, refer to the Masons Intertenancy Wall System pass™.



50mm Enviro AAC Panel

PBEJ25KG Enviro Glue AAC Mortar
CCHANNEL51x35x1.2 Steel C Channels
HCHANNEL51x35x1.2 Steel H Channels
RANGLEBKT75x45x50 Aluminium IT Wall Bracket

Mineral Wool (Fire Sealant) 1200 x 600 x 50mm

RANGLEBKT75x45x30 Mineral Wool (Fire Sealant) 1200 x 600 x 30mm
MTIESCREW45HD  12g x 45mm Screws
MTIESCREWHD 12g x 35mm Screws
 As supplied by Masons

Fire and Acoustic Sealant

Available in-store at:

TRADIES: This product might not necessarily be a stocked item by your merchant however can be ordered in.

MERCHANTS: To enquire about this product or to place an order, please contact your local Mason’s rep >